package com.srwl.mytx.utils;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ViewConfiguration;
import android.widget.ScrollView;

public class MyScrollView extends ScrollView {
    private int downX;
    private int downY;
    private int mTouchSlop;
    private ScrollListener scrollListener;

    public MyScrollView(Context context) {
        super(context);
    }

    public MyScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent e) {


        int action = e.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                downX = (int) e.getRawX();
                downY = (int) e.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                int moveY = (int) e.getRawY();
                if (Math.abs(moveY - downY) > mTouchSlop) {
                    return true;
                }
        }
        return super.onInterceptTouchEvent(e);
    }

    @Override
    protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {
        super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);
        if (scrollY == 0&&clampedY) {
            if (scrollListener != null) {
                scrollListener.onScrollToTop();
            }
        }//滑动到下边界
        else if (scrollY>0&&clampedY) {
            if (scrollListener != null) {
                scrollListener.onScrollToBottom();
            }
        }else if (!clampedY){
            if (scrollListener != null) {
                scrollListener.onScrollToMiddle();
            }
        }

    }

    public void setScrollListener(ScrollListener scrollListener) {
        this.scrollListener = scrollListener;
    }

    public interface ScrollListener {
        void onScrollToTop();

        void onScrollToMiddle();

        void onScrollToBottom();
    }
}